Wearable exoskeletons have been designed for medical, commercial, and military applications. Medical exoskeletons are designed to help restore a user's mobility. Commercial and military exoskeletons help prevent injury and augment the user's strength. Commercial and military exoskeletons are used to alleviate loads supported by workers or soldiers during strenuous activities, thereby preventing injuries and increasing their stamina and strength.
Exoskeletons designed for use by able-bodied wearers often act to improve the wearer's stamina by transferring the weight of a tool or load through the exoskeleton structure and into the ground, thereby decreasing the weight borne by the wearer. In some cases, tool-holding exoskeletons are outfitted with a non-anthropomorphic tool-holding arm that supports the weight of the tool, reducing user fatigue by providing tool-holding assistance. The tool-holding arm transfers the vertical force required to hold the tool through the exoskeleton-supported tool-holding arm rather than through the user's arms and body. In other cases, the exoskeleton structure is generally anthropomorphic and acts in tandem with the user's body to support some or all of the tool weight by supporting the positioning of the wearer's arms and then transferring that tool weight around the body of the wearer and into the ground. Weight-bearing exoskeletons transfer the weight of the exoskeleton load through the legs of the exoskeleton rather than through the user's legs. In some cases, weight-bearing exoskeletons are designed to carry a specific load, such as a heavy backpack. In other cases, military weight-bearing exoskeletons support the weight of armor. Commercial and military exoskeletons can have actuated joints that augment the strength of the exoskeleton user, with these actuated joints being controlled by the exoskeleton control system, and with the exoskeleton user using any of a plurality of possible input means to command an exoskeleton control system.
In powered exoskeletons, exoskeleton control systems prescribe and control trajectories in the joints of an exoskeleton, resulting in the movement of the structure of the exoskeleton and, in some cases, the positioning of a tool supported by the exoskeleton. These control trajectories can be prescribed as position-based, force-based, or a combination of both methodologies, such as those seen in impedance controllers. Position-based control systems can be modified directly through modification of the prescribed positions. Force-based control systems can also be modified directly through modification of the prescribed force profiles. As exoskeleton users and exoskeleton tools vary in proportion, variously adjusted or customized powered exoskeletons will fit each user somewhat differently, requiring that the exoskeleton control system take into account these differences in exoskeleton user proportion, exoskeleton configuration/customization, exoskeleton user fit, and tool support, resulting in changes to prescribed exoskeleton trajectories. The exoskeleton user can control changes in exoskeleton trajectories through communication with the exoskeleton control system through a variety of means, including but not limited to body pressure sensors, joysticks, touchpads, gestural sensors, voice sensors, or sensors that directly detect nervous system activity.
In unpowered tool-holding exoskeletons, the exoskeleton wearer provides the force to move the exoskeleton structure and any affixed tools, with the exoskeleton aiding the wearer by supporting the weight of tools in certain positions or aiding in certain tool or exoskeleton movements. In both powered and unpowered tool-holding exoskeletons, the design of the exoskeleton structure, and in particular the structure of the tool-holding arm and tool-holding arm attachment point, or the structure of the anthropomorphic arm that aids in tool support, plays a significant role in the usefulness of the exoskeleton to the wearer in tool use applications. The specific structure of the exoskeleton arm or tool support structure is variably suitable to specific tools and specific motions that the wearer may engage in.
There exists a need to provide a range of devices allowing for an exoskeleton to assist an exoskeleton wearer by directly supporting the weight of various tools and the use of these tools by the exoskeleton wearer, increasing the strength and stamina of the exoskeleton wearer in tool-using tasks. There further exists a need to provide additional devices allowing for an exoskeleton to support the arms of an exoskeleton wearer in such a way as to improve the strength and stamina of the exoskeleton wearer in tool-using tasks. There further exists a need to allow an exoskeleton wearer to use tool types or tools in ways that would not be possible without the exoskeleton. There further exists a need for an exoskeleton device allowing for the exoskeleton to provide power to tools, with the energy source for these tools being supported by the exoskeleton frame but not by the arms of the exoskeleton or wearer. There further exists a need to provide counterbalancing support to an exoskeleton to support the weight of the tool and exoskeleton structure supporting the tool.